In a vehicle brake hydraulic control apparatus, in an operation to stop a pump, if a suction valve is closed simultaneously with the stop of a motor, due to the inertial rotation of the motor, brake fluid may be drawn up by the pump to generate negative pressure between the suction valve and the pump, and cavitation may be caused. For example, JP-H10-035456-A discloses a technology to solve this problem.
In JP-H10-035456-A, when stopping the pump, after power to the motor is disconnected, the suction valve is closed after the passage of a given time, such that the inertia rotation of the motor ends during such given time, thereby preventing generation of negative pressure.
In JP-H10-035456-A, the given time is set for the time that is necessary from the disconnection of power to the motor to the stop of the inertia rotation of the motor according to the characteristic of the motor. However, this given time is set by taking into account worst cases of the structural variations of the motor, the pump or the like, the rotation number of the motor, a load applied to the motor, temperature, supply voltages and the like, that is, a case where the motor is most difficult to stop. Thus, the given time tends to be set for the time fairly longer than the actual time necessary for the motor to stop, and the suction valve is left open during this time. As a result, the time of power connection to the suction valve increases, thereby increasing the heat generation amounts of the coil and the ECU of the suction valve.